Essentials from the world of pearls

Monthly Archives: February 2014

There are two basic types of farmed pearls: bead nucleated and tissue nucleated. (The other main type classification is between cultured or farmed and natural or wild pearls)

Nucleation is the process which starts off the growth of a cultured or farmed pearl. It involves inserting something into a nacre-producing mollusc to trigger production of a pearl. This nucleus can be either just a tiny sliver of mantle tissue on its own or a sliver of mantle tissue plus a bead or other shaped foundation. In either case a nacre secreting pearl sac grows and a pearl is made within that sac.

Bead nucleated pearls include all tahitian and south sea pearls, akoya pearls and many modern big freshwater pearls (brands Edison and Ming) as well as fancy shapes such as coins or hearts.

Tissue nucleated pearls are mostly all freshwater pearls which are therefore all nacre, solid pearl. no bead inside. (Chinese and Biwa freshwaterpearls)

Keishi pearls are an exception. They are the pearls formed inside a usually pre-existing pearl sac from which a pearl has been removed (think of how a balloon looks when the air seeps out over time and you get the idea of a keishi pearl.

Mantle tissue is used because that is the area of tissue which specifically secretes nacre. It’s usually there to make the mollusc’s shell but will produce nacre wherever it is – a talent utilised by the pearl farmer.

Placement of the nucleus varies as well. Beads are placed in the sex organ – the gonad – of the mollusc and only one per mollusc. (You might think that this would stop the mollusc from wanting to reproduce but there is some research which indicates it make them more not less active!)

Tissue nucleated pearl grafts can be many to a mollusc and are placed in the mantle.

The new big thing (last three or so years only) in pearls are the big freshwater bead nucleated pearls from China. These are branded as Edison pearls or Ming pearls or are described as ripple pearls. They are big – up to 17mm, round or symmetrically baroque (because of the bead inside), have a lustre ranging from metallic to gloriously satiny, and a smooth to convoluted or rippled. They come in a range of natural colours from white to pink, purple, peach, gold, with greens and blues. (you can see our ripple pearls here and we have smooth surfaced Edison and generic bead nucleated pearls throughout the freshwater section ..here is one beautiful example of a bead nucleated Edison pearl necklace

Towards the end of the last buying trip to Hong Kong I spent a couple of hours poking through some smaller but very beautiful bead nucleated flameballs and baroques. I’ve yet to finish drilling the flameballs I collected for a necklace for myself (I need some hours from somewhere) but I did get to make two of these pearls into brooches last week.

Right from the start my imagination saw this pearl as a sleepy koala bear stretched out on a branch..one leg hanging down and head pillowed on branch and arms.

The lustre on this pearl is incredible, liquid metallic pearl white with rainbow overtones.

Sleepy koala

The second pearl will sit up on its own but is still now a brooch…I thought at first it was a cuddly furry rabbit or teddy bear, but have decided it’s a sitting on his haunches cuddly squirrel, with his tail curled to the side. Again amazing lustre and texture and a rainbow of overtones.

Squirrel pearl

To make each of these unique pearls into brooches we spent some time filing a deep and precise groove into the backs of the pearls, which exactly fits the base bar of the sterling silver brooch finding, which is glued into the slot to make the brooch.

You may remember the blue tahitian pearl which I wangled during the last Hong Kong buying trip….

Blue Tahitian pearl

Well, We just heard from its new owner who has made it into a beautiful pendant on a handmade silver chain necklace. Here it is

Blue tahitian pearl pendant and silver handmade chain necklace

Front view

Maker retired jeweller Dennis (who made this for his daughter) told us: ‘First I made a handmade chain, a slimmed down version of an antique pocket watch chain, with a matching adjustment section. It is finished with a small freshwater pearl as a charm. On the other end is a hook fastener in similar style.

The long links were made by stretching large O-rings

The bell for the pendant is like the calix of a mini-aubergine and the whole is a bit like regalia, but it is going overseas, where they are not shy about a bit of power dressing.’

Thank you for letting us know what you made Dennis – we send these pearls out into the world and we do wonder how they fare.

Can you please clarify regarding dimensions offered on pearl drops? Is this for the drop? If so what is the width

-Iwona

Pearls are always measured at 90 degrees (at right angles) to the drill hole if there is one, so for a drop pearl the measurement is indeed the width.

Ah-ha I hear you say. What about undrilled pearls? Well, my best answer would be that with round pearls you can’t tell and for anything else it is where the drill hole will be if there was one, if that makes sense.

Pearls are usually measured with accurate calipers. We use these neat and very accurate electronic ones when measuring pearls for uploading to the website

We measure everything in metric- it’s easier and more accurate. Even when pearl strand lengths are given in inches pearls are measured in mm. That isn’t logical but it is what happens!!

When pearls are being measured en masse to be made into strands or in lots of one specific size they are usually sieved. It took me a while to work out what the pervasive and distinctive rattly noise of pearl sieving was when I first heard it. But it is very accurate too as a way of measuring pearls.

calipers

but purely mechanical ones are fine too and are most often used in Hong Kong and China.

Our measurements are accurate to fractions of a millimeter, which is pretty small , but you need to be aware that pearls are organic and will vary a little between strands.

(Many auction etc sellers just copy over the wholesalers size description but these can be inaccurate by a mm or more.)